• Fred Hadidi

Under pressure: The independent claim goes down in a tire pressure monitoring case, but a few depen

Wasica Finance GmbH, et al. v. Continental Auto Systems, Inc. et al.

2015-2078, 2015-2079, 2015-2093, 2015-2096, Decided: April 4, 2017

Case Summary

Wasica Finance GmbH and Bluearc Finance AG own U.S. patent 5,602,524, which describes systems for monitoring tire pressure in vehicles. Continental Auto Systems, Inc. challenged several of the claims in an Inter Partes Review proceeding; Schrader-Bridgeport International, Inc., and two other entities challenged the same patent in a separate IPR proceeding.

The only independent claim of the ‘524 patent states: (a) that data taken from a pressure transmitting signal is displayed; and (b) that the pressure transmitting signal need only be “representative of the air pressure” within the tire. In an attempt to distinguish over prior art asserted in the IPRs, the patent owner (Wasica) argued that the claim must be limited to the display of numeric tire pressure data only. The PTAB disagreed, and found the claim to be unpatentable over prior art references that disclosed non-numeric tire pressure data that was “representative” of the air pressure within the tire. The U.S. Court of Appeals for the Federal Circuit (Federal Circuit) affirmed, holding that a non-numeric signal can be “representative of” air pressure in much the same way as a vehicle’s gas warning light might symbolize a low fuel level without displaying a numerical value of remaining fuel volume.

In the same appeal, patent owner Wasica challenged the PTAB’s invalidation of dependent claim 17, which requires a transmitter within a wheel to “recognize[] emittance of a predetermined switching signal.” Wasica argued below that the term “emittance” must be construed to cover wireless signals only; the Board disagreed, holding this language to cover both wired and wireless communications, and finding the claims unpatentable over a reference that sent an analogous switching signal over a wire. The Federal Circuit affirmed the PTAB’s claim construction, noting that “the ’524 patent is rife with exemplary embodiments where the switching signal propagates in both wireless and wired form.”

Although the PTAB invalidated claims 1 and 17, it found dependent claims 6-9 and 20 to be patentable; petitioners Continental and Schrader challenged these rulings in their cross-appeals. Claim 6 requires the transmission of “electromagnetic waves of constant frequency acting as carrier waves.” Both parties had argued below that a prior art reference to Oselin anticipates this claim because it discloses constant frequency carrier waves, but the Board rejected this argument, finding Oselin “unclear” as to whether its transmissions occur at a fixed frequency.

The Petitioners took different positions in their respective cross appeals.Schrader made the following arguments: (1) based on evidence in the record,Oselin discloses that its transmitters are all tuned to a “common” working frequency; and (2) based only on arguments made by its attorneys, Oselin’s transmitters must use a constant frequency. The Federal Circuit rejected both. Like the PTAB, the Court found Oselin’s disclosure to be ambiguous,and therefore affirmed the ruling of patentability. And regarding Schrader’s attorney argument, the Panel explained that anticipation is an inquiry viewed from the perspective of one skilled in the art, and therefore unsupported attorney argument is irrelevant.

Continental’s argument regarding claim 6 was essentially that Oselin discloses a genus (the reference says it can employ “any modulation scheme”), which anticipates the species recited in claim 6 (“electromagnetic waves of constant frequency”). Like the PTAB, the Federal Circuit rejected this argument, stating the general proposition that “disclosure of a genus in the prior art is not necessarily a disclosure of every species that is a member of that genus.” Continental also made an obviousness argument regarding claim 6, which the Court rejected because it was not presented in the IPR petition, and concluded with the following: “shifting arguments in this fashion is foreclosed by statute, our precedent, and Board guidelines.”

Finally, both petitioners cross-appealed the Board’s ruling that dependent claim 9 is patentable; this claim requires a transmitter to send data to areceiver through “at least a 4 bit sequence” having four smaller “bit sequence[s]” of information. The issue at the PTAB and on appeal was whether the phrase “bit sequence” should be construed either as a sequence of “one or more bits” or “two or more bits” The Board adopted the latter construction; the Federal Circuit reversed, explaining that the Board’s construction conflicted with disclosed embodiments in which a bit sequence includes only a single bit.

Click here for the PDF



Silicon Valley Office • (650) 325-0220

Boston Office • (774) 571-3513